Traditionally, corrosion has not been treated as a process variable phenomenon. Thus, no significant effort has previously been made to perform plant operation analysis based on real-time corrosion measurements, or to identify the potential impact corrosion might have on plant operation, particularly from the standpoint of associated economic impact.
Even with the advent of computers and advanced process control techniques, plant operation analysis has largely been limited to measurement of conventional process variables, such as temperature, pressure, and flow rates; values obtained from on-line analyzers, for example, chemical composition data; and values derived from chemical engineering estimation formulas, for example, flood percentages, etc.
Such variables are typically considered as input/output variables in dynamic predictive control models designed to determine optimal plant operating conditions, which take into account the likely future impact of the variables with respect to the subject process.
To date, however, there has been no known attempt to provide a dynamic predictive control model that incorporates highly precise real-time corrosion measurements in such a manner that the corrosion-related factors are adequately considered in relation to the economic impact of corrosion on plant operation and maintenance costs.